80's old school

iTrader: (7)

Problem about taking your car to a "non-emission" county is that when you try to renew your registration in an "emission" required county it will be a no go!

Check to make sure, but I am sure the state government is not that stupid! Come on.....this is Texas!!

av8or1

iTrader: (4)

You're giving the government, any government, far too much credit.

To be open, I know several folk who do this sort of thing routinely. 'Never have a problem renewing the registration either. 'Makes the system look like a joke, but then I do have sympathy with a lot of the types of folk who circumvent in this manner, as they simply cannot afford the cost of correcting the issues with their vehicles let alone buying something new, so....funny stuff....

Thanks,

Jerry

av8or1

iTrader: (4)

Thank you for the tip. I had this in mind already actually, as the Mazdatrix website stakes the same basic claim that you have; something to the effect that 90%+ of the time a GSL-SE won't pass emissions it's due to the ACV. Interesting to see you agree with that notion, based on your experience with the SMOGing in CA...I've talked to a couple of rotorheads who didn't seem to think so, but whatever, it's just as good of a place to start as anywhere.

Thanks again, letcha know what I find out...

Jerry

j9fd3s

iTrader: (3)

you should see some of the piles of crap ive gotten to pass, by just making sure the acv is blowing into the exhaust PORT.

since its an -se, you should also check that little valve over by the cruise control, if thats bad it wont pass either

80's old school

iTrader: (7)

I really do sympathize with the people who do not have the financial means to correct their car to get it to pass emissions. I mean people who are a little low on jack need to drive too.

I am sure there are also ways to "trick-****" the system to get your car registered. Luckily now I don't have to do that.

Problem is, in about 2 more years we will be re-locating back to California. My 80 would have a better chance passing a kidney stone than passing a CA emission test!!!

I think when we move back, we will have to "work" the system a little. I think I will keep my Mazda still registered in Texas. Texas laws "luckily" allow to keep a car registered in Texas even if you move out of state.

av8or1

iTrader: (4)

Hmmmmm...ok I'll play, are you talking about the little t-fitting?

Thanks

av8or1

iTrader: (4)

UPDATE:

Ok tonight I made time to get back out and work on the 7. I'd be interested to see if any of the more experienced rotorheads would care to comment on my findings, especially those who have been so kind to chime in already (thanks!).

And off I went. Turned her over to let it warm up, per the FSM. My pressure gauges have mysteriously grown legs, so I decided I'd have to skip over checking the air pump, figuring that if air was coming out of the ACV then the pump must be doing it's thing ok, though a good measurement is still in order, naturally. (reasonable assertion?)

The ACV test showed the following:
-> Air is flowing out of the ACV port to be "dumped overboard" and how. This is happening at idle and at the higher RPMs specified in the FSM.
-> No air is flowing out of the relief solenoid valve.
-> No air whatsoever is coming out of the split air hose port on the aft side of the intake manifold.
-> No air is coming out of the switching solenoid valve either, though the FSM doesn't state that it should be, so I punted on making a determination here, though my guess is that this is correct behavior.

Diagnosis:
Because no air is coming out of the aft port of the ACV and then passing through the check valve on its way to the main cat, there isn't enough O2 in the main to assist in fully burning the HCs. In short, whatever amount of air it is that is coming from the air pump is simply being vented overboard and that's all she wrote. The likely culprit is a bad ACV and possibly also a bad relief solenoid valve.

Plan of action:
Even though it's pricey, replace the ACV and the relief valve too, though I'm not convinced that I actually need to do the latter, anyone care to comment on that? (ergo does this test indicate that the relief valve is also bad or is that just a side effect of the bad ACV?)

Caveats:
This, of course, may not completely solve the problem enough such that my 7 will subsequently pass emissions. The cats, especially the main, might also need replacing. Then there's the air pump test which I can't do until I buy new pressure gauges, though I suspect it's doing ok, as I felt a significant amount of air coming out of the vent port with an increase in RPMs. Then there's the engine itself, it may just be not burning clean enough and need a rebuild. And finally the tune up that I haven't gotten to yet, that could enter the equation also.

Finally, I am including some photos partly to help those who may come along in the future and be searching for this information, as I was. I like to help when I can, though I'm still somewhat new to rotaries (lotsa piston stuff though). The other part of posting is to ask a question of the more experienced regarding what happens to the overflow air that comes out of the relief port of the ACV. See the last 3 photos...it passes out of the port, through the tube and into a small "squeeze tube" kinda-looking thing, through another hose and then into a cannister looking deal. My guess is that these are simply silencers to help reduce the engine's noise, making it more in-line with any noise restrictions and also more pleasant to the ear. Correct? I mean what exactly are these little do-dads? What I couldn't figure out was why there are two of them, like a pre-silencer and then the big boy (Mini-Me and Dr. Evil)? And finally, is there any kind of air cleaner in these devices to help clean the air before it is released into the atmosphere?

Thanks!

Jerry

j9fd3s

iTrader: (3)

diagnosis is wrong. air DOES NOT go to the cat, it actually needs to go thru the valve, intake manifold, into the center iron and down into the exhaust ports.

i'm not 100% sure what does what (one is relief, one is switching), but both diaphrams on the valve, need to see vacuum and hold it in order for it to work.

the solenoids are basically rpm vs throttle switched, so if the tps is bad, it wont work, but thats kinda rare.

ratboy

iTrader: (1)

I just got my 85 SE inspected but had to go outside austin (dripping springs) to do it. A few shops gave me hassles for one reason or another (only 1 cause my reg says travis, other reasons: not cats, blinker doesnt lock, ground too wet to do inspections???, inspector @ lunch, etc) but I eventually got it done on my 6th try. I also told them I just moved to the area which then they said I had to sign the waiver saying I wouldnt drive the car in Travis Co. I got out of that by convincing them that my car was exempt - safety only after 24 years (but it actually doesnt start until 25+). Just give it a shot and try it that way (slightly illegal) and if that doesnt work I know there are people on here with inspection hookups in austin (more illegal and co$tly!). Good luck!

av8or1

iTrader: (4)

Ok, I'll go back and take another look at the FSM to make sure I'm on the right page here. For now however, I'll have to disagree with you. My understanding is that the ACV directs air to one (possibly more simultaneously???) of three places:
1) the cat
2) the exhaust
3) the relief ("dump it overboard")

And there is a port on the back of the intake manifold that has a tube connected to it and that tube extends down below the firewall and runs the length of the pipe into the main cat. I'll take photos the next time I'm under there. So to me that says that air IS indeed being injected straight into the cat as well as the exhaust, as you are advocating.

Regardless, however you slice it, the FSM says that air should be coming out of the aforementioned aft port on the manifold. It's not. That means that the ACV is bad according to what I've read, as it is the ACV that should be sending "fresh air" out of that port.

Well as I said, there are three functions that the ACV does and to do that it actually contains three switches internally, not only two that you are stating. But I'll take another look at the FSM to make sure I'm remembering that correctly. It was spelled out pretty clearly however, so again, for now I'll stick to my guns and say that one of the switches does indeed send air straight to the cat.

On that much we agree straight-away.

Thanks for the input!

Jerry

av8or1

iTrader: (4)

Hey ratboy,

Thanks for the input. Yeah, I suppose I could do that, but I don't like skirting the law in general, even a bit, so I'll stick to the high road on this one. Besides, in the worse case scenario I "mothball it" for 7 months (where "mothball" means to drive it around the block regularly to keep things in running order, at least somewhat) and then it won't matter.

In the larger picture however, it seems like what you do with your car depends on what your purpose for it is. For my 85 SE I plan to keep it as stock as it is currently, which is completely stock. For me this means being overly **** by retaining the emissions control crap and keeping all of it in working order. Call it my "purist" offering, if you will. Crazy as that may sound. Now with my 84, well that's a different animal altogether.

Are you a part of the TEXAS RXs? I need to join that soon!

Thanks for the help though, 'preciate it!

Jerry

av8or1

iTrader: (4)

Ok I had another look tonight at the FSM. Plus my 85. And my 84. Conflicting results between the two cars.

First, some errata from my previous posts:
1) In my original report of my findings, I typed in that no air was coming out of the relief solenoid valve nor the switching valve. I meant to type "into", as these are "innies", not "outties".
2) In the follow-up post I talked about 3 switches internal to the ACV; I of course meant to write "valves", there are valves inside the ACV, not switches! (sometimes I type too fast for my own good)

So....tonight I decided to perform the same test on my 84, figuring that if the ACV worked on it, I'd just take it off and put it on the 85 then block off the ACV ports on the 84 with one of those $10 blocking plates.

See the attached photos. I have a break in my tubing that leads up to both the relief and switching solenoid valves. This line extends from the vacuum switch in the upper-most right corner of the engine bay. Thus no air is being drawn into either solenoid valve. On my 84, this is working ok. When I disconnect the line to the switching solenoid, I can hear a definite hiss; nothing on the 85.

What concerned me about the results was that when I disconnected the split-air hose off of the aft port on the manifold on the 84, I did feel some air coming out of it. Not as much as I thought there would be. Definitely more than on my 85 however. Lots of air was being vented overboard on the 84, just like with the 85. I also noticed that when I increased the engine speed and then let it decelerate again, I heard that "back popping" noise that was being discussed in another thread, it was audible and obvious on the 84. Not so much on the 85.

So...I dunno. I'll repair the vacuum lines on the 85 and see what happens. I doubt that this will correct the problem such that the ACV begins to function again, but it's worth a try. Then take it from there.

Any input? I'm headed out of town again on the 22nd and this weekend is Mother's Day weekend, so I don't know when I'll get back to this. Hopefully next week. Letcha know what happens.

Thanks,

Jerry

ratboy

iTrader: (1)

My car already had the stock manifolds and cats removed so it was wayy out of my price range to get it to pass emissions for just 7 months. And when I looked into the waiver route it was gonna cost me more money (and time) so that wasnt realistic either.

I would just get some good silicone tubing and replace all of your vaccum lines. There are a ton under the dynamic chamber and when I pulled mine off most of them were pretty cooked and most of the splitters were broken. While you're at it you could also pull your injectors and send them off for cleaning and flow testing. I saw huge improvements in my car after this same work.

Im a member of the texasrxs but this is the first time Ive had a reliable and legal rotary in quite a while so I may actually make a meeting or cruise now.

j9fd3s

iTrader: (3)

the bad thing about the shop manual is it really doesnt tell you WHY, http://www.jimrothe.com/mazda/84_tra...ual/index.html

the acv has 2 valve/plunger/diaphrams, giving a total of 3 places it can direct air.

1. with no inputs at all, the valve is in "relief' ie it will take the air pump air and just bypass it to the external dump.

2. with vacuum at both diaphrams, the valve is in 'port' air, so all of the air pump air goes into the exhaust port. this is how it should be between idle ~2500 rpm (its throttle dependent, so the rpm varies).

3. 'split air' this is when the relief is 'on' and the switching is off. its really only used at cruise and transient conditions, its not in use during any kind of state emissions testing. i have smogged rx7's with the split air pipe removed, just to prove the point.

so if you want to check the valve, apply vacuum to each plunger/valve/diaphram, it should retract the piston, and hold it there. it does come apart too, so sometimes they are repairable. i have had things like the airpump come apart and the broken pieces get stuck in the acv

av8or1

iTrader: (4)

Ah, I see. I had the same issue with the waiver option; didn't wanna do that anyway, so no big loss there.

Yeah, 'got all that planned down the line but I may have to step it up if this preliminary work doesn't correct the issue. See my next post.

Ok great, well lemme know when you're going and I'll join ya. I'm gonna look into how to join the group tonight.

Thanks,

Jerry

av8or1

iTrader: (4)

Ok, this stuff I understand and it's more helpful than the FSM, which you are correct to state that it doesn't tell you why. Not so much about the what either, but I digress. Thanks for the feedback, I've saved your comments off to my RX7 notes document, which has grown to be a monster in and of itself. More to come I'm sure.

So tonight I decided to fiddle around with it a bit more before I get busy again. Interesting results. I replaced the fitting and reconnected the vacuum lines from the vacuum switch through the cruise control and onto the relief SV and switching SV. 'Started it and let it warm up while I look at the FSM a while. Go back to have a look-see, and with little surprise the switching SV now sucks in air like nobody's business. As I'm carefully examining the SVs and the general tubing everywhere to see if I can spot any other compromises therein, I notice small amounts of smoke rising from somewhere underneath the bay. "Whazzhat? I've never seen that before!" I think to myself and then I remembered when I pulled all of that crap off of the second pre-cat. I walk around to the front and have a look underneath to see what's going on. Sure enough indeed the second pre-cat is RED hot and smoke is eminating from around it. It's difficult to tell from where exactly, but not important. Time to shut things down. I look back into the bay once more and notice that the tach I'd hooked up wasn't reading correctly. I juiced the throttle a bit and it registers correctly. I had bumped the ground somehow, but what was important was that the throttle assembly is hot too, more so than I've noticed in the past. So I turn 'er off.

Hmmmmmmmm......well now I know what all of that wryenolds wrap stuff was doing: masking the deodorant of a bigger problem. Obviously this cat will need replacing, and who knows maybe it is clogged...good thing I just bought a bunch of pre-cats off of some non-rotary guy in CA who had stumbled across them, didn't care and just wanted to be rid of them! I'll probably take the main off and take it to a shop to see if it is any good while I'm at it...

So that's the latest. [sigh]

Thanks,

Jerry

av8or1

iTrader: (4)

Ok so I decided to replace the second pre-cat before doing anything else. The trouble is that all of the ones I purchased were/are first pre-cats, not second. Crap. I found an online parts catalog (after a lot of searching) and was confused by the detailed listing for the second pre-cat. It says:

D-CODE DESCRIPTION PART NO QUANTITY MODEL/DESCRIPTION

40 400A CONVERTER NO 2, PRE N249-40-400B 1 M T
N250-40-400B 1 A T

(couldn't figure out how to indent properly, sorry...)

I've pretty much decided to simply pull the #2 off of my project 84 SE, see if it's any good and just use it if so. However, I must admit that this entry in the parts catalog has me puzzled. Anyone know what the difference is and what the "M T" and "A T" mean? Am I missing something simple here? (probably, but...)

Thanks,

Jerry

PercentSevenC

I would assume automatic transmission vs. manual transmission.

av8or1

iTrader: (4)

Thanks %7C...I was thinking that was the meaning but I kept saying to myself "...nah, can't be that simple..." - shows you what I get for thinking.

Ok, less talk, more do. I leave on Friday for 10 days as it is...

j9fd3s

iTrader: (3)

it'll pass without the precats, one of mine passed with a header, and a friend car passed the high speed part of the test without a cat at all! (failed the idle test though)

av8or1

iTrader: (4)

Yeah, I figured as much. However as I said earlier in this thread, I'm keeping the pre-cats only for "originality sake", if you will. The second one is having issues and needs replacing. It was causing a potential fire hazard, so it seems wise to replace it before I do anything else.

That having been said, I researched these little pre-cat critters last night and learned that they exist primarily to be a catalyst after startup until the engine is warm. Ok I'm gonna go ahead and ask a "stupid" here: Is it correct to say that they can do this because they're physically closer to the header and thus hotter exhaust?

It was asserted that they don't do anything once the engine is warm; that there might as well be straight pipe in their place. The only way I can understand that is if their physical size is just too small to make any real difference once the exhaust has reached its normal operating temperature. Is that correct?

Apologize in advance for the fundamental questions, 'just never seen pre-cats before buying my RX7s.

Thanks!

j9fd3s

iTrader: (3)

no problem! one of the HUGE differences between the state emissions testing and the federal testing of these cars is that the original EPA tests were done starting the car cold.

essentially imagine if they put a big giant plastic bag on the tailpipe, started the car cold, ran it thru a test loop, and then measured the contents of the bag. the cars were allowed a certain weight of each pollutant to be able to be sold here new.

to pass a test like this, the converter has to be up to temprature very fast, and the simplest way to do this is to put it closest to the hottest thing, the engine.

the car also needs more catylist when its cold as it needs to run a richer mixture (well kinda, over 65C and its normal).

it works too, if you fire up a working 3 cat car (the precats are usually hollow after 60k), it seems like it passes a sniffer test after about 30 seconds of run time. although the state test numbers dont vary much with or without precats

a STATE emissions test by contrast just samples from two points, with the car hot. its a much different test. in CA our test is even in the "wrong" place, compared to the epa testing